4. Organization Catalogs : 4.3 Working with Catalogs : 4.3.8 Selecting Networks
   
4.3.8 Selecting Networks
The impact of using a catalog on network connectivity is subtly different depending on whether vApp network or organization virtual datacenter network types are in use.
4.3.8.1. Internal vApp Networks
When a vApp containing internal vApp networks is deployed, the configuration of the internal networks is consistent with the configuration at the time the vApp was added to the catalog. The configuration, including firewall rules, is predefined and does not need to be updated. A user with the appropriate permissions can change this configuration.
The exception to this rule is when you use network address translation (NAT) with the default one-to-one mapping configuration. All virtual machines connected to the given vApp network use this NAT configuration automatically, regardless of any change you made when creating the vApp. For example, if a vApp containing three virtual machines is created and mapped to an organization virtual datacenter network with NAT, three NAT-routed IP addresses are allocated. Although it is possible to disable these IP addresses manually as in the LAMP stack example, changes are lost when the vApp is deployed from the catalog. For the changes to remain in effect, use the port forwarding approach where all rules are retained as they would be for firewalls.
4.3.8.2. Organization Virtual Datacenter Networks
For a vApp and its associated virtual machines to have connectivity outside the vApp, the virtual machines must be connected to an internal or external organization virtual datacenter network. Available organization virtual datacenter networks are usually created and defined by an organization administrator. When the vApp is deployed, it is automatically attached to the organization virtual datacenter network defined when it was created and uploaded to the catalog. It is also possible for the user to select which network to connect to the virtual machine.
A vApp deployed from a published catalog created in a different organization might have a different or invalid network defined, in which case the user should select a valid organization virtual datacenter network and attach the vApp.